I. Field of the Invention
This invention relates generally to apparatus for refurbishing pipes, valves, flanges and the like in industrial plants, such as power generation facilities, petroleum pipeline facilities and the like, and more particularly to a portable lathe machine that can be rapidly set up and used in the field to accurately machine flat or beveled surfaces on pipe flanges, valve, fittings and pipe ends within close tolerance ranges.
II. Discussion of the Prior Art
Various portable machines for performing different machining operations are known in the art. In the refurbishment of industrial tubing, such as is found in refineries, pipelines, steam power plants and the like, it is often necessary to cut through a pipe and then perform one or more end prep operations, such as beveling, facing, threading, etc. to thereby facilitate the joining of pipe ends or flanges. The Wachs et al. U.S. Pat. No. 4,411,178 describes a typical prior art machine for end prepping pipes and piping components. In that machine, separate drive motors are required for causing radial and axial feed of the tool. The feed rates are controlled by controlling the speed of the two motors. Moreover, the design reflected in the Wachs et al. '178 patent precludes the tool slide and tool supported thereby to be placed at an angle to the base plate 30, thus making it more difficult to accurately bevel the end of a pipe workpiece.
The present invention also comprises an improvement over my earlier portable end prep machine described in U.S. Pat. No. 4,799,409. For example, in that earlier design, no provision is made for an adjustable radial feed rate of the cutting tool, nor is any provision made for tilting the tool slide at a desired angle to the axis of the pipe to facilitate mitering or beveling of the pipe end being machined. Further, no provision is made for accurately gauging movement in the axial feed direction as an operator manually attempts to adjust axial displacement of the housing on which the tool head is mounted.